<template>
  <div class="goods-image">
    <!-- 放大镜图 -->
     <div class="large" :style="[{backgroundImage:`url(${images[currIndex]})`},largePositions]" v-if="show"></div>
     <!-- 中图 -->
    <div class="middle"  ref="target">
      <img :src="images[currIndex]" alt="" >
      <!-- 遮罩层 -->
      <div class="layer" :style="layerPositions" v-if="show"></div>
    </div>
    <!-- 小图 -->
    <ul class="small">
      <li v-for="(img,i) in images" :key="img" :class="{active:i===currIndex}">
        <img @mouseenter="currIndex=i" :src="img" alt="">
      </li>
    </ul>
  </div>
</template>
<script>
import { reactive, ref, watch } from 'vue'
import { useMouseInElement } from '@vueuse/core'
export default {
  name: 'GoodsImage',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    const show = ref(true)
    const target = ref(null)
    // 放大镜图
    const largePositions = reactive({
      backgroundPositionX: 0,
      backgroundPositionY: 0

    })
    // 遮罩层
    const layerPositions = reactive({
      left: 0,
      top: 0
    })
    const { elementX, elementY, isOutside } = useMouseInElement(target)
    watch([elementX, elementY, isOutside], () => {
      show.value = !isOutside.value
      const position = { x: 0, y: 0 }
      if (elementX.value < 100) {
        position.x = 0
      } else if (elementX.value > 300) {
        position.x = 200
      } else { position.x = elementX.value - 100 }

      if (elementY.value < 100) {
        position.y = 0
      } else if (elementY.value > 300) {
        position.y = 200
      } else { position.y = elementY.value - 100 }
      layerPositions.left = position.x + 'px'
      layerPositions.top = position.y + 'px'
      largePositions.backgroundPositionX = -2 * position.x + 'px'
      largePositions.backgroundPositionY = -2 * position.y + 'px'
    })
    return { currIndex, show, largePositions, layerPositions, target }
  }
}
</script>
<style scoped lang="less">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
    z-index: 500;
 .large {
   position: absolute;
   top: 0;
   left: 412px;
   width: 400px;
   height: 400px;
   box-shadow: 0 0 10px rgba(0,0,0,0.1);
   background-repeat: no-repeat;
   background-size: 800px 800px;
   background-color: #f8f8f8;}
  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
   position: relative;
   cursor: move;
   .layer {
     width: 200px;
     height: 200px;
     background: rgba(0,0,0,.2);
     left: 0;
     top: 0;
     position: absolute;
   }
  }
  .small {
    width: 80px;
    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      &:hover,&.active {
        border: 2px solid @xtxColor;
      }
    }
  }
}
</style>
